Strange Malfunction??? Total gun Lock up.

[TACAV]

Had this happen yesterday. I have never had this type of malfunction ever with any of my ARs and I was wondering what might have caused it or if this was a fluke or something.

Info and Specs of carbine at time of malfunction:

Daniel Defense factory lower
Noveske MK18 factory upper
Ammo: American Eagle Red box M193 55gr.
Gen 1. Magpul PMag with window
BCM Medium Gunfighter Charging handle
Gun setup had only approximately 500 rounds through it before this happened. So hardly any.
I have no extra gizmos like aftermarket BAD levers or strange bolt assists.

Prior to this no issues with gun.

Weapon was cleaned, lubed, and function tested before going to the range. I also pre loaded all of my mags at home and inspected the feed lips etc before packing them up for the range.

I had fired about 150-200 rounds after zeroing the Aimpoint and running some drills when this happened...

Was shooting a fully loaded 30 round Pmag. Bolt locked back on empty. I hit the magazine release, empty mag dropped free. I inserted a new fully loaded 30 round Pmag and gave it a quick tap on the bottom and confirmation tug. It was locked in. I slapped the bolt catch. Nothing happened. Tap the mag/racked the charging handle. Mushy charging handle where it just flopped back all lose but the bolt was still locked to the rear.

(Did a transition and finished my drill :) )

Went to go fix my gun.
I observed that there was no round chambered or stripped out of the magazine. Or any spent casing stuck in the upper receiver. The top cartridge was still seated properly in the magazine.

Bolt was firmly locked to the rear, charging handle was useless, bolt catch locked open. I tried to strip the magazine out. The magazine release button pressed in normally however the magazine would not budge at all. It was 110% stuck. Usually if you tug hard enough the magazine can wobble just a little but it was locked in frozen solid with absolutely no play at all.

Forward assist did nothing.
The safety still worked...

Being ever aware of down range I tried to separate the upper from the lower, the take down pins came out however the upper and the lower would not budge.

Using dummy rounds in the past I know you can separate the upper from the lower...

Again, it would not budge.

I took a picture looking through the ejection port cover but all I had was my cellphone in super bright light, and it did not come out well. Really though every thing looked fine. Just as if you inserted a loaded magazine into the mag well with the bolt locked to the rear.

Everything was totally locked up. I had to eventually use a small screw driver to individually slide every individual cartridge out of the magazine into the chamber and then tilt my gun muzzle up to get the loose round to fall out. x30.:suicide2: I inspected the top cartridges, especially the first one. They were all fine.

I then had to chisel my Pmag out of my lower with a screw driver and a mallet. My hammering is what caused the scuff marks on the right side of the feed lips and that small hole at the rear.

http://i474.photobucket.com/albums/rr105/TACAV/DSCN3926.jpg

When I was bashing my magazine out I did it over a table in case some broken part or piece of something that might have caused the lock up fell out. Nothing did.

Once the magazine was finally out and after an inspection of the gun, every thing looked OK. I used different magazines (I had 10 with me) and the gun functioned fine for the next several hundred more rounds I went through until I stopped shooting for the day.

I function tested the questionable magazine with loaded dummy rounds. It worked fine and function tested fine. I did not try anything with live ammo.

The only thing I did differently on this day at all was I used all 30 round mags as the ammo I had been loading was packaged in 30 round boxes. I usually download by 2 for easier mag insertions but I really don't see how that would be the problem.

I have not been able to replicate this issue since. I am just trying to rack my brain out of curiosity what could have been the issue, and if there is/was any preventative measures I might need to take in the future.

Thanks for any input.

[steelonsteel]

hit the bottom of the mag too hard on insertion perhaps?

[wilco423]

I've done the same thing (magazine over-insertion), but only when going to prone when doing a mag change with an open bolt. I hit it pretty hard, and it took two people to get the mag separated from the lower. If, on insertion, you really just gave the magazine a tap and nothing more, I'd just get rid of the mag and drive on. Current Pmags are easier to over-insert than metal mags, but the new, slim versions have a shelf built into them to prevent it.

Might not be a bad idea to check the mag catch area for loose plastic shavings.

[Sticks]

Had this happen yesterday. I have never had this type of malfunction ever with any of my ARs and I was wondering what might have caused it or if this was a fluke or something.

Info and Specs of carbine at time of malfunction:

Daniel Defense factory lower
Noveske MK18 factory upper
Ammo: American Eagle Red box M193 55gr.
Gen 1. Magpul PMag with window
BCM Medium Gunfighter Charging handle
Gun setup had only approximately 500 rounds through it before this happened. So hardly any.
I have no extra gizmos like aftermarket BAD levers or strange bolt assists.

Prior to this no issues with gun.

Weapon was cleaned, lubed, and function tested before going to the range. I also pre loaded all of my mags at home and inspected the feed lips etc before packing them up for the range.

I had fired about 150-200 rounds after zeroing the Aimpoint and running some drills when this happened...

Was shooting a fully loaded 30 round Pmag. Bolt locked back on empty. I hit the magazine release, empty mag dropped free. I inserted a new fully loaded 30 round Pmag and gave it a quick tap on the bottom and confirmation tug.
Never tap/slap a mag on an open bolt. Insert it, hear/feel the click and it's in, Tug on it if you feel the need.


It was locked in. I slapped the bolt catch. Nothing happened. Tap the mag/racked the charging handle. You just made it worse, and no doubt hit it a littler harder than you think. When you "Slapped the bolt catch", did you smack the side of your rifle with your hand, or simply push the button? Look at your hand when you "Slap". There is a large concave section of soft flesh, surrounded by a bony rim. You may have felt the button, but you applied little to no pressure to it. Insert the mag, slide your hand up the magwell after the mag is inserted with your fingers on the chamber side of the receiver until your thumb reaches the bolt release, then use your thumb and push the button. You can add more leverage to the button with your fingers on the opposite side by squeezing and raising your elbow at the same time. You might have gotten lucky and the bolt catch might have been able to push the mag back down and gotten some bolt movement. Likewise it might have wedged between the mag and the receiver.


Mushy charging handle where it just flopped back all lose but the bolt was still locked to the rear.

(Did a transition and finished my drill :) )

Went to go fix my gun.
I observed that there was no round chambered or stripped out of the magazine. Or any spent casing stuck in the upper receiver. The top cartridge was still seated properly in the magazine.

Bolt was firmly locked to the rear, charging handle was useless, bolt catch locked open. I tried to strip the magazine out. The magazine release button pressed in normally however the magazine would not budge at all. It was 110% stuck. Usually if you tug hard enough the magazine can wobble just a little but it was locked in frozen solid with absolutely no play at all.

Forward assist did nothing.
The safety still worked...

Being ever aware of down range I tried to separate the upper from the lower, the take down pins came out however the upper and the lower would not budge. Because the bolt was inside the receiver extension. That is one big pin that you are not going to remove short of unscrewing your receiver tube, or clearing what ever has it blocked in front of the bolt.

[TACAV]

Thanks guys and thanks sticks.

[Bacon Six Actual]

A quick tip to prevent this when you're doing immediate action drills, instead of tapping, slapping, or any variation of striking the floorplate, grab the mag and push/pull to insure that it's locked. If you thump the shit out of a mag with bad feed lips that you might not have noticed previously, you could have a volcano on your hands. A quick push/pull is quiet, more efficient, and less likely to cause problems like an over inserted mag. Under stress you tend to hit things a lot harder than you think.

[shua713]

Thanks for sharing, I will now be more careful with inserting pmags and not slap them in hopes of not having these issues

[Sticks]

Thanks for sharing, I will now be more careful with inserting pmags and not slap them in hopes of not having these issues

It's not just Pmags, any mag.

[Pog926]

Nice to know. Thanks for sharing.

[ridgerunner70]

Thanks for sharing

[feedramp]

Thanks, good to know!

[ssracer]

This happened to a friend at a carbine class during malfunction drills. He got a little over aggressive inserting the new mag on an open bolt and jammed it in just as you described. Took about 20 minutes to get the PMAG out and have the gun operational again.

[SicTransit]

Thanks for sharing, I will now be more careful with inserting pmags and not slap them in hopes of not having these issues

:lol:

[Fenix1442]

Magazines are like women, you don't slap them. Treat them right and they will take care of you.:jester:

[GrumpyM4]

Had this issue pop up today during our training session.

My buddy inserted a tan Pmag, slapped the base and it wouldn't come out until I managed to muscle**** the bolt back and lock it.

It came out pretty easily after that.

[SMETNA]

I once had to mortar a stag I once owned because of a bad reload one of my friends gave me to try out for accuracy testing. Went bang, didn't eject or move the BCG an inch.

I figured the case was to large or the brass was too soft due to being loaded one too many times. Could've had a tight chamber on that stag too I suppose.

Glad you found the culprit